Students are able to change their level on the updated RazKids. To prevent this from happening you can lock the students level.
Sign into with your Raz-Kids teacher account
Select My Classroom/Roster
Select the individual student/Edit Student Info
Select "Reading Room Settings"
Under the levels, select "Level(s) Below Student Level and Above Student Level Lock At Level J Through Level K"
You can choose 0 levels above/below or 1 level above/below.
Select "Save and Close"
See image below: